Digital advancements like the Internet, e-book readers, and even your phone may have put a crimp in the sales of traditional books, but they haven't been able to slow down the rare book market. In fact, a 400-page book of psalms that dates back to 1640 is about to be auctioned off, and is expected to sell for over $30 million. Here are some other old, rare page turners that sold for big bucks.

1. James Audubon's Birds of America

One of the bestselling rare books is a first edition of Birds of America by acclaimed artist and ornithologist James Audubon. The book, which dated back to 1827 and had 435 hand-drawn illustrations, was sold at auction to an anonymous buyer for more than $10 million. The book itself was more than 3 feet in length because Audubon wanted his birds to appear life-size on the page. He also drew the printing plates for his birds in black and white and a number of artists had to hand paint them with watercolors, an expensive process that drove up the price of his book even in his time.

2. A "First Folio" of William Shakespeare's Works

A first edition of a book by one of the greatest writers of all time (if you don't ask high school English students who are required to read the plays in order to graduate) fetched a pretty penny in 2006—$2.8 million, to be exact—at a Sotheby's auction in London. The book is actually considered one of the least rare since approximately a third of the 750 original copies are still in existence today.

3. Edgar Allan Poe's Tamerlane and Other Poems

America's biggest rare book sale to date goes to a copy of Poe's very first book. A first edition of Tamerlane and Other Poems, a book that Poe claimed he wrote just before he turned 14, sold at a Christie's auction in 2009 for $662,500. Only 50 copies were ever printed, and scholars believe that only 12 are currently in existence. Another copy of the book also held the previous U.S. rare book sale record: It went for $225,000 almost 20 years before the 2006 auction.

4. Nicolaus Copernicus's De Revolutionibus Orbium Colestium

A first print of Copernicus's first book, in which he theorized that the Earth revolved around the sun, took home a huge chunk of change in 2009. A buyer from Christie's auction house paid more than $2.2 million for the well-preserved book (title translated to On the Revolutions of the Heavenly Spheres). It was the highest price for a rare book sold at an auction where the first telephone book, printed two years after Alexander Graham Bell invented the device, went for $170,000.

5. Leonardo da Vinci's Codex Leicester

The notes and drawings of one of mankind's greatest men is also in the hands of the one of its richest. Microsoft founder and entrepreneur Bill Gates spent more than $30.8 million for an original copy of da Vinci's famous manuscript that the artist and inventor first penned in 1508. Then, rather than just watch it collect dust in his archives, Gates had digital copies made of the manuscript and put them online as part of a virtual exhibit with the British Library.

6. The Guo Family Library Collection

Individually, the books in this collection may not have sold for big bucks, but as a collection, they made for an impressive sale. Guo Yunlou sold his family's collection of 1292 books, some of which dated back to the 1820s during the reign of China's Qing dynasty, for a staggering 216 million yuan ($34.2 million) at a Beijing auction house last year. It took six generations of his family to amass and care for the collection, which included an 80-volume encyclopedia of flowers.

7. Action Comics No. 1

It may not be as enlightening as the first copy of the Magna Carta or as intellectually stimulating as a first edition of Thornton Wilder's The Bridge of San Luis Rey, but that didn't stop one collector from writing a huge check for the first Superman comic book, published in 1938: It sold at an auction in 2011 for a whopping $2.16 million, the highest price for a comic book of any kind. The comic once belonged to actor Nicolas Cage, who reported it stolen from his Hollywood home in 2000. It surfaced again in April 2011 when someone bought an abandoned Southern California storage locker and found the missing comic among its contents.

8. Golf: Luxury Edition

This book was also a recent print, but the company that published it felt that its rarity and "luxury" merited a more expensive asking price. Wonderland Publications put together a carefully handcrafted book about golf in 2011 and offered an extremely expensive "luxury edition" that readers could pick up for the low, low price of $48,000. The huge price tag wasn't just paying for what went into the book but also what went on it. All 140 pages were hand torn and bound together in a cover made from 400-year-old Russian hide leather. Only 10 were made.

Honorable Mention: Tomas Alexander Hartmann's The Task

This 13-page book isn't very old, but it is very rare and very expensive. German artist and writer Tomas Alexander Hartmann only commissioned one copy of his book, and he put it on the market in 2008 for an asking price of 153 million Euros ($199,940,400). A press release announcing the book's release and first public appearance claimed that Hartmann put such a steep price on it because he took more than 30 years to come up with the words for his 13-page book, and he believed the price was merited because he "sees himself as the greatest philosopher of all time." In 2009, the artist put the book back on display for the final time, reportedly because he "tired of the many questions he finds himself confronted with," according to a press release. There is no indication that he has found a buyer—so far.